Mercurial > hg > nginx
view src/http/modules/ngx_http_auth_request_module.c @ 7629:f47f7d3d1bfa
Mp4: fixed possible chunk offset overflow.
In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming
the "mdat" atom, chunk offsets are casted to off_t values which are typically
64-bit signed integers. A specially crafted mp4 file with huge chunk offsets
may lead to off_t overflow and result in negative trim boundaries.
The consequences of the overflow are:
- Incorrect Content-Length header value in the response.
- Negative left boundary of the response file buffer holding the trimmed "mdat".
This leads to pread()/sendfile() errors followed by closing the client
connection.
On rare systems where off_t is a 32-bit integer, this scenario is also feasible
with the "stco" atom.
The fix is to add checks which make sure data chunks referenced by each track
are within the mp4 file boundaries. Additionally a few more checks are added to
ensure mp4 file consistency and log errors.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 26 Feb 2020 15:10:46 +0300 |
parents | f01ab2dbcfdc |
children | d26db4f82d7d |
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/* * Copyright (C) Maxim Dounin * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_str_t uri; ngx_array_t *vars; } ngx_http_auth_request_conf_t; typedef struct { ngx_uint_t done; ngx_uint_t status; ngx_http_request_t *subrequest; } ngx_http_auth_request_ctx_t; typedef struct { ngx_int_t index; ngx_http_complex_value_t value; ngx_http_set_variable_pt set_handler; } ngx_http_auth_request_variable_t; static ngx_int_t ngx_http_auth_request_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_auth_request_done(ngx_http_request_t *r, void *data, ngx_int_t rc); static ngx_int_t ngx_http_auth_request_set_variables(ngx_http_request_t *r, ngx_http_auth_request_conf_t *arcf, ngx_http_auth_request_ctx_t *ctx); static ngx_int_t ngx_http_auth_request_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static void *ngx_http_auth_request_create_conf(ngx_conf_t *cf); static char *ngx_http_auth_request_merge_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_auth_request_init(ngx_conf_t *cf); static char *ngx_http_auth_request(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_auth_request_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_auth_request_commands[] = { { ngx_string("auth_request"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_auth_request, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("auth_request_set"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2, ngx_http_auth_request_set, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_auth_request_module_ctx = { NULL, /* preconfiguration */ ngx_http_auth_request_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_auth_request_create_conf, /* create location configuration */ ngx_http_auth_request_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_auth_request_module = { NGX_MODULE_V1, &ngx_http_auth_request_module_ctx, /* module context */ ngx_http_auth_request_commands, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_http_auth_request_handler(ngx_http_request_t *r) { ngx_table_elt_t *h, *ho; ngx_http_request_t *sr; ngx_http_post_subrequest_t *ps; ngx_http_auth_request_ctx_t *ctx; ngx_http_auth_request_conf_t *arcf; arcf = ngx_http_get_module_loc_conf(r, ngx_http_auth_request_module); if (arcf->uri.len == 0) { return NGX_DECLINED; } ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "auth request handler"); ctx = ngx_http_get_module_ctx(r, ngx_http_auth_request_module); if (ctx != NULL) { if (!ctx->done) { return NGX_AGAIN; } /* * as soon as we are done - explicitly set variables to make * sure they will be available after internal redirects */ if (ngx_http_auth_request_set_variables(r, arcf, ctx) != NGX_OK) { return NGX_ERROR; } /* return appropriate status */ if (ctx->status == NGX_HTTP_FORBIDDEN) { return ctx->status; } if (ctx->status == NGX_HTTP_UNAUTHORIZED) { sr = ctx->subrequest; h = sr->headers_out.www_authenticate; if (!h && sr->upstream) { h = sr->upstream->headers_in.www_authenticate; } if (h) { ho = ngx_list_push(&r->headers_out.headers); if (ho == NULL) { return NGX_ERROR; } *ho = *h; r->headers_out.www_authenticate = ho; } return ctx->status; } if (ctx->status >= NGX_HTTP_OK && ctx->status < NGX_HTTP_SPECIAL_RESPONSE) { return NGX_OK; } ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "auth request unexpected status: %ui", ctx->status); return NGX_HTTP_INTERNAL_SERVER_ERROR; } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_auth_request_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ps = ngx_palloc(r->pool, sizeof(ngx_http_post_subrequest_t)); if (ps == NULL) { return NGX_ERROR; } ps->handler = ngx_http_auth_request_done; ps->data = ctx; if (ngx_http_subrequest(r, &arcf->uri, NULL, &sr, ps, NGX_HTTP_SUBREQUEST_WAITED) != NGX_OK) { return NGX_ERROR; } /* * allocate fake request body to avoid attempts to read it and to make * sure real body file (if already read) won't be closed by upstream */ sr->request_body = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t)); if (sr->request_body == NULL) { return NGX_ERROR; } sr->header_only = 1; ctx->subrequest = sr; ngx_http_set_ctx(r, ctx, ngx_http_auth_request_module); return NGX_AGAIN; } static ngx_int_t ngx_http_auth_request_done(ngx_http_request_t *r, void *data, ngx_int_t rc) { ngx_http_auth_request_ctx_t *ctx = data; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "auth request done s:%ui", r->headers_out.status); ctx->done = 1; ctx->status = r->headers_out.status; return rc; } static ngx_int_t ngx_http_auth_request_set_variables(ngx_http_request_t *r, ngx_http_auth_request_conf_t *arcf, ngx_http_auth_request_ctx_t *ctx) { ngx_str_t val; ngx_http_variable_t *v; ngx_http_variable_value_t *vv; ngx_http_auth_request_variable_t *av, *last; ngx_http_core_main_conf_t *cmcf; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "auth request set variables"); if (arcf->vars == NULL) { return NGX_OK; } cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module); v = cmcf->variables.elts; av = arcf->vars->elts; last = av + arcf->vars->nelts; while (av < last) { /* * explicitly set new value to make sure it will be available after * internal redirects */ vv = &r->variables[av->index]; if (ngx_http_complex_value(ctx->subrequest, &av->value, &val) != NGX_OK) { return NGX_ERROR; } vv->valid = 1; vv->not_found = 0; vv->data = val.data; vv->len = val.len; if (av->set_handler) { /* * set_handler only available in cmcf->variables_keys, so we store * it explicitly */ av->set_handler(r, vv, v[av->index].data); } av++; } return NGX_OK; } static ngx_int_t ngx_http_auth_request_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "auth request variable"); v->not_found = 1; return NGX_OK; } static void * ngx_http_auth_request_create_conf(ngx_conf_t *cf) { ngx_http_auth_request_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_auth_request_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->uri = { 0, NULL }; */ conf->vars = NGX_CONF_UNSET_PTR; return conf; } static char * ngx_http_auth_request_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_auth_request_conf_t *prev = parent; ngx_http_auth_request_conf_t *conf = child; ngx_conf_merge_str_value(conf->uri, prev->uri, ""); ngx_conf_merge_ptr_value(conf->vars, prev->vars, NULL); return NGX_CONF_OK; } static ngx_int_t ngx_http_auth_request_init(ngx_conf_t *cf) { ngx_http_handler_pt *h; ngx_http_core_main_conf_t *cmcf; cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module); h = ngx_array_push(&cmcf->phases[NGX_HTTP_ACCESS_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_auth_request_handler; return NGX_OK; } static char * ngx_http_auth_request(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_auth_request_conf_t *arcf = conf; ngx_str_t *value; if (arcf->uri.data != NULL) { return "is duplicate"; } value = cf->args->elts; if (ngx_strcmp(value[1].data, "off") == 0) { arcf->uri.len = 0; arcf->uri.data = (u_char *) ""; return NGX_CONF_OK; } arcf->uri = value[1]; return NGX_CONF_OK; } static char * ngx_http_auth_request_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_auth_request_conf_t *arcf = conf; ngx_str_t *value; ngx_http_variable_t *v; ngx_http_auth_request_variable_t *av; ngx_http_compile_complex_value_t ccv; value = cf->args->elts; if (value[1].data[0] != '$') { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid variable name \"%V\"", &value[1]); return NGX_CONF_ERROR; } value[1].len--; value[1].data++; if (arcf->vars == NGX_CONF_UNSET_PTR) { arcf->vars = ngx_array_create(cf->pool, 1, sizeof(ngx_http_auth_request_variable_t)); if (arcf->vars == NULL) { return NGX_CONF_ERROR; } } av = ngx_array_push(arcf->vars); if (av == NULL) { return NGX_CONF_ERROR; } v = ngx_http_add_variable(cf, &value[1], NGX_HTTP_VAR_CHANGEABLE); if (v == NULL) { return NGX_CONF_ERROR; } av->index = ngx_http_get_variable_index(cf, &value[1]); if (av->index == NGX_ERROR) { return NGX_CONF_ERROR; } if (v->get_handler == NULL) { v->get_handler = ngx_http_auth_request_variable; v->data = (uintptr_t) av; } av->set_handler = v->set_handler; ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[2]; ccv.complex_value = &av->value; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } return NGX_CONF_OK; }